Oswaldella delicata Pena Cantero, Svoboda & Vervoort 1997

• Main Authors: Molinero, A. González, Peña Cantero, A. L.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2015
• Subjects: Biodiversity; Taxonomy; Animalia; Cnidaria; Hydrozoa; Leptothecata; Kirchenpaueriidae; Oswaldella; Oswaldella delicata; Antarc*; Antarctic; Livingston Island; South Shetland Islands
• Online Access: https://doi.org/10.5281/zenodo.6107443; http://treatment.plazi.org/id/03C287C628097C13D4F48D332EB17ADD

Oswaldella delicata Peña Cantero, Svoboda & Vervoort, 1997 (Figs 2, 16 B, 17B, 19B) Material examined. Spanish Antarctic Expedition Bentart 95: Stn 28A , BIO Hespérides , 2 February 1995, 62°12.1297’S, 60°23.1833’W (South Shetland Islands, north of Livingston Island), 126 m (Department of Zoology, University of Valencia, BENTART 95-28A). Description. Monosiphonic, unbranched stems, up to 60 mm high, divided into internodes. Angle between cauline apophyses and stem ca. 45°. Cauline apophyses with single axillary nematophore, emerging through perisarc hole provided with very short collar-shaped nematotheca (Fig. 2 B, C). Hydrocladia unbranched (Fig. 2 A), some bifurcated. First hydrocladial internode bifurcated, with two similar prongs. Mesial superior nematophore emerging behind free part of adcauline hydrothecal wall. Mesial inferior nematophore on a strongly marked swelling at proximal third of internode; with well-developed, nail-shaped nematotheca (Fig. 2 D–F). Hydrotheca elongate, placed on middle of internode. Adcauline wall with distinct free portion. Abcauline hydrothecal wall roughly straight, but basally convex (Fig. 2 E). Hydrothecal aperture circular, more or less perpendicular to long axis of internode (Fig. 2 D–E); rim even. Gonothecae fusiform with subterminal circular aperture. Remarks. Our study has confirmed the presence of a single axillary nematophore in the cauline apophyses, as previously described (Peña Cantero et al . 1997; Peña Cantero & Vervoort 2004). However, it is noteworthy that our study has provided evidence of the presence of a little-developed, previously unnoticed, collar-shaped nematotheca associated with that nematophore (Fig. 2 B–C). Published as part of Molinero, A. González & Peña Cantero, A. L., 2015, SEM study of species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa, Kirchenpaueriidae), with an annotated checklist of the species of the genus, pp. 401-441 in Zootaxa 4052 (4) on pages 403-406, DOI:10.11646/zootaxa.4052.4.1, http://zenodo.org/record/245887